Isolation And Identification Of Piglet Diarrhea Pathogens From A Farm In Shaanxi Province

Piglet diarrhea is a serious disease induced by microbial pathogens(viruses, bacteria, etc.), feeding conditions, sudden decrease of environmental temperature and so on. Bacterial diarrhea is an important reason, which affects healthy growth and leads to death. The purpose of this study was isolation and identification of bacterium of piglet diarrhea from a large-scale piggery in Shaanxi Province. Drug sensitive test on the bacteria may provide the large-scale piggery a reference for the effective prevention and treatment of bacterial diarrhea in piglets.(1)43 anal swabs of diarrhea piglets within 30 day-ages were collected from a large-scale piggery in Shaanxi Province from October 2014 to April 2015. Colony morphology, Gram staining, cultural characteristic, biochemical test were tested. The results showed that bacteria had been isolated from all the 43 pathological samples and 100% isolates were E.coli(43/43), 18.60% isolates were Proteus(8/43), 16.28% isolates were Streptococcus faecalis(7/43), 13.95% isolates were Bacillus(6/43), 9.30% isolates were Staphylococcus(4/43), 9.30% isolates were Yeast(3/43) and 2.33% isolates were Salmonella(1/43).(2)The 3 strains of E.coli were randomly selected from suspected clinical cases. The pathogenicity tests in mice showed that two strains could respectively caused dead of all 3 mice at about 18 h post-inoculation, indicating that the pathogenicity of the E.coli was very strong. The serological tests showed that the two strains were O141(2 strains), other one strain was O20. The 3 mice were inoculated by the Salmonella, who died at about 13 h post-inoculation, indicating that the pathogenicity of the Salmonella is very strong. The serotype identification showed that it was Salmonella typhimurium group B(S.typhimurium), O4. There were no obvious change of mental condition and diet desire in mice inoculated by O20 and Proteus, indicating that the isolated strains were very weak or not pathogenic. Genome sequences of suspected Salmonella and Proteus were determined by NCBI blast gene alignment software. The homology between the sample sequences and the target sequences was 99%, then they are identified as Salmonella and Proteus.(3)Drug sensitivity test results showed that the E.coli were sensitive to Gentamicin, Ciprofloxacin, Neomycin, Kanamycin, Streptomycin and Enrofloxacin, part of them were resistant to Tetracycline, Ampicillin. Salmonella was sensitive to Ceftriaxone, resistant to Gentamicin, Tetracycline, Ampicillin, Neomycin, Kanamycin, Streptomycin, Enrofloxacin. Proteus was sensitive to Gentamicin, Ciprofloxacin, Kanamycin element, Streptomycin, Enrofloxacin and resistant to Ceftriaxone, Tetracycline, Ampicillin.In summary, the medicines such as gentamycin, kanamycin and neomycin could be selected to treat piglet diarrhea caused by E.coli and Ceftriaxone could choosed to treat piglet diarrhea caused by Salmonella. E.coli was an important pathogenic bacteria in the cause of diarrhea piglets. The most important pathogen was E.coli in piglet diarrhea. Isolation rate of Salmonella was low and was Salmonella typhimurium, The Salmonella typhimurium was resistant to most antibiotics.